1. Field of the Invention
The present invention is directed to a method and to an apparatus for producing X-ray exposures of body parts of a human, particularly X-ray tomograms of the jaw or skull of a patient, whereby a ray beam generated by a radiation source and limited by a diaphragm aperture of a primary diaphragm strikes a detector arrangement after penetrating through the exposure subject, the detector arrangement having at least one X-ray image-acquiring detector element.
2. Description of the Prior Art
Methods and apparatuses are employed in dental radiology with which it is possible to produce tomograms of a human, particularly of the region of the jaw. A particular application is the production of tomograms whose slice proceeds perpendicular to the mandibular arch. Such tomograms are called transversal sections. Compared to otherwise standard panorama tomograms, such transversal sections exhibit an especially small range of the depth of field. European Application 0 229 971 discloses an apparatus with which such tomograms are produced on an X-ray film.
European Application 0 632 994 discloses an apparatus for producing X-ray exposures digitally. To this end, a line detector camera with a detector that is implemented as a single-stage or multi-stage CCD sensor is provided. Dependent on whether a single-stage or multi-stage sensor is employed, the dimensions of the detector arrangement typically amount to 135 through 180 mm in the image height and approximately 6 mm in the image width. These dimensions take into account, first, the image acquisition size necessary for a good diagnosis and, second, an adequate depth of field when viewing the individual slices. It has been shown in practice that the diaphragm system and detector system must be matched such that the usable ray fan for transversal slices, i.e. for the aforementioned transversal sections, must exhibit a width of at least 20 mm in the detector plane in order to be able to achieve a range of approximately 1 through 3 mm for the depth of field. A detector arrangement on the order of the aforementioned size is comparatively expensive with current technology.